Jumping/stalling

[tonicaek]

Hey guys,
Bit of an issue here! A few weeks ago I felt a slight jolt whilst driving the moggie and it's getting progressively worse.
Whilst accelerating the engine seems to be cutting out, making the car rock and jolt, and occasionally when static it stalls. The odd thing is that it's intermittent, it'll be fine one minute and coughing the next.
The only thing we're done so far is check the distributor cap, which seems fine.

Any suggestions?

[chrisryder]

It could be the ignition coil breaking up. or the condenser in the distributor. The coil is easier to change than the condenser, but also more expensive! You could get a coil, and fit it. if that doesn't cure it, you've got a spare!

[tonicaek]

Just taken him out aaaaand.. He's now dead. Turning over, but not starting. Coil would make sense - I'll order one.

[taupe]

Also worth checking the flexible wire from the distributor terminal to the points and the earth cable within the distributor connecting the contact baseplate to the casing. These sometimes break within their cloth cover and only fail when the ignition is advancing under acceleration -showing as an annoying intermittent fault.

[bmcecosse]

It's 'never' the coil...... Check everything else first - bad connections/points gap/low volts lead (inside the dizzy)/condenser/rotor arm/dizzy cap.

[Neil MG]

Sounds like it could be a loose connection on the low tension side, check the wire from coil to distributor. The fact that is runs well then not at all suggests a bad electrical connection.

[simmitc]

Take out the spark plugs and earth one of them. Ignition on, crank engine - is there a spark?

Remove fuel hose from carb and place in a container. Ignition on. Does fuel flow - if no, then it's the fuel pump. Try banging it - not a permanent repair, but helps prove a point. Make sure that you replace the hose properly, and BE CAREFUL with petrol, no naked flames, sparks, heat etc.

[tonicaek]

Hey guys, just thought I'd conclude the saga - seems it's not always 'never' the coil - fitted the new on Saturday and he's running like a beaut!
Thanks for the guidance on this one.

[bmcecosse]

Often it's loose connections at the coil.......coils either work or don't work . Glad you got it fixed, but out of interest - try the old coil again to see if the problem returns.

[tonicaek]

I retract that comment. Driving to town this morning and bam, completely cut out. Just got back from two hours in the freezing cold.
A bad connection would sound about right - now he struggles starting, and when he does it's deathly lumpy then cuts out. When we replaced the coil the lead really didn't want to go on, and the boyfriend's attempts only disfigured the connectors (the joys of having someone else to blame!)
I bought the cheaper of two replacement coils, but later read somewhere on here that there were issues with cheaper ones?
The recovery guy checked it over and he thought the chances are it's the petrol pump, which was my first assumption when the issues started, but it had been running perfectly all weekend after the new coil was fitted.
Roll on weekend..

[dalebrignall]

i tend to sgree with bmc i had a new coil and the connectors were different sizes ,its worth cheacking they are tight are all the plug leads fitted to the dizzy cap correctally.ive had that happen too the king lead connection being loose .

[Nuffles]

I had the same problems as described and it was my fuel pump. Starting would be fine but it would just randomly cut out while I was driving. The engine stopped on Tescos roundabout at rush hour Five minutes later and having hit the fuel pump a few times and it started up fine, but the stalling got progressively worse until I had to stop and hit the fuel pump 4 times on a 3 mile stretch of road on the way to work New fuel pump totally sorted it. For a month or so before the total cut outs it would 'hiccup', often when accelerating with my foot down (using more petrol I guess). I'm going to get myself some spare points and fix the old pump to keep in the boot from now on.

[dalebrignall]

i got a new fuel pump 3 years ago fixed the old one put it in the boot and not needed it ,but the day i take it out i will .

[tonicaek]

I think it's the HT lead between the coil and the distributor causing the problem, when fitting the new coil - after having first attempted to connect it - the car started the same is it currently does then died. After some fiddling, poking, prodding and manipulation of the connectors with a pair of pliers it was reconnected and worked fine, I was able to jaunt about the place over the weekend with no problem.
Trouble is, the damage the boyfriend caused to the connectors may mean I need to replace the brand new coil I've just bought, as well as a new set of HT leads.
If the connectors aren't the same size, how do I go about making sure any that I order do fit?

And Nuffles - you've just described exactly what happened! I hit a 40 stretch, tried accelerating and it wasn't having it - as you say - it was hiccupping, then cut out. I suppose I should be glad it gave me warning! Still not fun when you're in a live lane, emerging from an underpass with traffic merging from the left..

[simmitc]

Have you tried the checks I suggested earlier? The symptoms say that it's either fuel or ignition (ie not mechanical damage) so you need to isolate which it is. I'm still verging towards the fuel pump. Strangely enough I had one only two weeks ago that was playing up. When the car stopped, unusually hitting the pump made no difference, but removing the fuel pipe from the carb allowed fuel to start flowing again, and it worked long enough to get home and fit a new pump.

You could also have a condenser failing - they can be intermittent. Quick, cheap, and easy to change. If it makes no difference, then keep the old one as a spare.

Also, check that the piston in the carb is free to move up and down without sticking (sorry, can't remember if we've covered that already).